Cold forging machine



Nov. 21, 1944. w. E. BOLLAND CbLD FORGING MA CHINE Filed Dec. 20 1945 v4 Sheets-Sheet l 20 wawz Nov. 21, 1944:

W. E. BOLLAND COLD FORGING MACHINE Filed Dec. 20, 1 943 4-Sheets-Sheet 2Nov. 21, 1944. wisoLLANn 2,362,970, r

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' Nov. 21, 1944.

.' E. BOLI AND ,362,970

Patented Nov. 21 1944 i U I 2,362,970 co n FORGINGMACHINE' ,swiuiamEdmundi'Bolland, Ne'ohells, Birmingham,

.-Birmingham, England ApplicationfDecembei 20; 1943, Serial No. 515,073

- "In Great Britain March 5, 1943 7 2 Claims. fc1.1c-12') Y vj inventionrelates to 'niultiblow cold forg} ing machines of thekind adapted toform hexagonal or other heads onlengths of steel or other metal rod orwire intended" to serve as bolts, rivets or the like. At the presenttime there is used for, this purpose awell; known two-blow automaticmachine consisting of a-die,'a pair of punches which operatesuccessively 'on one end each work. piece, a crank-actuated toggleine'chanismfor imparting the operative movements to the punches, andmeans for intermittently'feeding to the die the'metal to be headed.Ordinarily the metal stock is in theform of a coil, "and the free end ofthe coil which is fed into the die serves to eject from-' the die theEngland, assignorto H. Newton & Co -Ltd 'quired lengthcan be fed andremoved succes sively by handga slide carrying punches which are movablerelatively to thedie, a rotary memher for actuating the slide, and aclutch for transmitting m'otionfrom a source to the said-member,"the-clutch being under the control of the attendant andbeing'ad apted' to disconnect the 7 said member from the sourceautomatically at th end of each work cycle. a

In the accompanying sheets of explanatory drawings: 1

Figure 1 is a part sectional side elevation, and

I Figure 2 a part sectional plan, of a two-blow cold the line '3-3 ofFigure 2..

previously headed piece which has beensevered 4 i'roxn the stockbyacutting means forming apart I "of th machine. The'mo'de. of :actionof themachine isbriefly as follows; Afters work piece hastbeenfedinto'the diegitzisgrip-ped by the latter, and then the first punchcomes into action for forming a swelling on the adjacent end of the workpiece, this movement'of the slide which car.-

forging machine embodying the invention.

Figure 3 is a sectional side elevation taken on 'Figure4 is afragmentary sectional view taken on the line 4-4 of Figure 2.,

Ties both punches being efiectedduring one-half of arevolution of thecrank which actuates'the toggle mechanism. Then the punches'are, movedrelatively to the slide to bring the other punch into position, andduring the next half revolution of the crank the second punch causes thefinal shape to be imparted to the head on the work piece; ,On releaseofthe work piece bythe die it is ejected by the next feed movement of thestock. This machine operates continuously, in that each cyclefollows itspredecessor without intermission. v

Adisadvantage of theabove described machine is that-there is=a limit tothe length of the work pieces which can be dealt with, this being due.to the fact that the finished work pieceis ejected. automatically by theincoming work piece,

and that suflicient space must be allowed between the adjacent ends'ofthe die and punch slide to permit this action. The amount of spacepermissible sets a limit to the. length of the work piece that can bedealt with, and consequently it is impossible with such. a machine tulforge headsonwork pieces exceeding a certain. length. The machine,however, possesses great advantages over other forms of headingmachines, and'thc problem to which our present invention is directed isthat of construci'ng a machine which whilst retaining the mainadvantages of a machine, such as that above described; enables workpiecesof any length to be dealt with.

The'invention consists of a multi-blo'w'heading machine havingincombination adie to and mm which work pieces previously cut to the re-Figures 5, :6 and 7 aresimilar fragmentary sectionalviews drawn-to alarger scale than, Figures 1to 4,.and illustrating the manner in whichthe v punches act on the work piece.

,In-carrying the invention into effect as shown, I employ amachinercomprising a main frame a,

a transverse driving shaft b carried by bearings c on the frame, ahorizontally movable slide 6 supported between longitudinal guides f onthe ;frame, toggle mechanism g through which the slide=is operable by acrank i on the driving shaft 'andwhich serves to impart two operativestrokes to the slide in each rotation of the driving shaft,

a verticallymovable slide. 7 mounted onthe front ,end'of thehorizontally movable slide and carry- .ing a pair. of punches k, ksituated one above the other, link and lever mechanism m through whichthe vertically movable slide is actuated from a cam n on the drivingshaft to bring the punches successively .into an operative positionduring "each rotation of the driving shaft, a die 0 supported by thefront end of theirame and having fixed and movable parts 0 0 betweenwhich the work piece as (indicated by broken lines in Figure 1), isgripped whilst being subjected to the action of the punches, and asecond toggle device q operable through a slidable member r and a levers from a second cam t on the driving shaft to .actuatethe movable partof the die.

The machine so far described is of conventional form'wi'th theexceptionthat the worksevering means usually employed are dispensedwith, and that work pieces (in the form of pieces I of metal rod or wirecut to the required length) can be successively inserted into andremoved from the die o by hand. Thus, in'the example shown theworkpieces as p can be inserted into upper side of the die and allowedto fall out through the underside of .the die.

It will be understood that the cavity 2) in the die is shaped in theusual manner to enable a hexagonal or other head to be formed on one endof each work piece as p under the successive action of the punches k, 70

Figures 5 to 7 illustrate the manner in which the punches k, k act onthe work piece 12 in the die 0. In Figure 5 the first punch k is shownin the operative position which it occupies immediately prior to actingon the work piece 13.. In this position the punch k is coaxial with thework piece p, the latter having been gripped between the die parts 0 owith the end to be headed projecting to the required extent from therear of the die. The operative stroke of the first punch It causes theprojecting end of the work piece :1 to receive a bulbous form. as shownin Figure 6, whereupon this punch is withdrawn and the second punch kcaused to assume the operative position previously occupied by the firstpunch. The operative stroke of the second punch k causes the bulbous endof the work piece 10 to fill the die cavity 1) and form the requiredhexagonal or other head on the work piece,.this condition being shown inFigure '7.

For determining the extent to which the work piece 10 projects from therear of the die 0 prior to the heading operation, I employ a stop in theform of an arm w on one end of a rod :11, the latter being rotatablysupported by bearings 1: s0 arranged on the frame a at one side of thehorizontally movable slide a that by appropriate oscillatory movementsof the rod the arm can be moved into and out of an operative position inwhich its outer end lies opposite to the rear end of the die cavity.Near the end remote from the arm w the rod :0 is cranked (as shown inFigures 1 and'2) so that this end of the rod can co-operate with a thirdcam 11 on the driving shaft 1). This cam y serves to move the rod a: inthe direction for moving the arm into its operative position, theopposite movement of the rod being effected under the control of the camby a torsion spring 2 on the rod. When the machine is at rest the arm 10occupies its operative position in which it serves as a stop for thework piece being inserted into the die o. At the commencement of eachrotation of the driving shaft 1) the arm w is moved under the action ofthe spring 2 to an inoperative position clear of the punches k, Id, andat the end of each such rotation the arm is returned by the cam to itsoperative position against the action of the spring.

For imparting the required motion to the driving shaft 17 I employ afly-wheel 2 adapted to be driven continuously by a belt (not shown) froman electric motor or other power source. The fly-wheel 2 is carried by ahollow boss 3 on one side of an annular member 4 which is rotatablymounted on the driving shaft b. If desired the fly-wheel may be rigidlysecured to the annular member 4 by a nut 5, on the outer end of theboss, but preferably annular friction discs 6 are arranged between thesides of the fly-wheel and the adjacent surfaces of the nut and annularmember to permit relative rotational movement between the fly-wheel andannular member in the event of the machine being over loaded. At theside remote from the boss 3 the annular member 4 is formed with a recess1 for accommodating the adjacent side of a second annular member 8secured on the driving shaft b. The two annular members 4, 8, formcoaxial parts of a clutch which enables the continuously rotatingfly-wheel 2 to be connected to the driving shaft h under the control ofthe attendant, and which automatically disconnects the shaft from thefly-wheel at the end of each rotation of the shaft. The two clutchmembers 4, 8 are interconnectible by a spring-loaded key 9 which ismounted in a radial hole in the member 8 and is adapted to engage eitherof a pair of recesses l 0 in the inner peripheryof the member 4. The key9 is controlled by a catch lever ll pivoted to a bracket l2 on the framea, and is adapted to act on a shoulder l3 on the key. The catch lever His operable by a cam-shaped lever l4 also pivoted to the bracket l2,this latter lever being connected by link and lever mechanism I5 to apedal I6. Moreover, the camshaped lever I4 is loaded by a spring I!which is stronger than the spring l8 employed for loading the key 9, andwhich serves normally to hold this lever in the position (shown in fulllines in -Figure 3) in which the catch lever II holds the key 9 clear ofthe inner periphery of the clutch member 8 on the driving shaft b. Whenthe key 9 is in this condition the fly-wheel 2 and the associated clutchmember 4 can rotate freely on the driving shaft b.

Depression of the pedal 16 by the attendant serves to move thecam-shaped lever I4 against the action of its loading spring I1. to aposition shown in broken lines in Figure 3. The effect of this is torelease the key 9 which under the action of its loading spring l8 entersone of the recesses ill in the rotating clutch member 4, when the latterassumes an appropriate position, and serves by contact with a hard metalabutment piece is in this recess to transmit motion to the other clutchmember 8 and the driving shaft b. When the driving shaft b commences torotate the pedal I6 is released by the attendant, and the ensuingmovement of the cam-shaped lever l4 under the action of its loadingspring [1 causes the catch lever II to assume a position in which itserves automatically to return the key 9 to its initial operativeposition at the end of a complete revolution of the driving shaft 1),thus bringing the machine to rest. During this revolution of the drivingshaft b a work piece is headed as previously described, and when themachine is brought to rest the headed workpiece is removed from the die0 and another work piece is inserted preparatory to the pedal l6 beingagain depressed to cause a repetition of the above described operations.

Whilst the rate of output of the machine forming the subject of myinvention is less than that of an ordinary two-blow cold forging machineadapted to operate on short work pieces, it is nevertheless much greaterthan that of other means or methods at present used for heading longwork pieces, and moreover it enables the same high quality ofperformance to. be obtained as is produced by the usual two-blowmachines. The invention is not, however, limited to twoblow cold forgingmachines, but may be applied to three-blow or other multi-blow coldforging machines.

Having thus described my invention what I claim'as new and desire tosecure by Letters Patent is: v

1. A multi-blow cold forging machine of the kind specified, having incombination a die to and from which work pieces previously cut to therequired length can be fed and removed suc cessively by hand, a slidecarrying punches which ,are movable relatively to the die, a rotarymember for actuating the slide, and a clutch for .transmitting motionfrom a source to the said memberfithe clutch comprising a pair ofcoaxial parts,

2. A multi-blow cold forging machine of the kind specified, having incombination a die to and from which work pieces previously cut to o therequired length can be fed and removed successively by hand, a slidemovable relatively to the die, punches carried by the slide and movablerelatively thereto so as toact in succession on each work piece fedto-the die, a rotary member for actuating'the slide, and a clutchadapted to I be brought into action under the control of the attendantfor transmitting motion from a source to the said member, and to be putout of action automatically after the punches have performed theirfunction on a'work piece.

WILLIAM EDMUND BOLLAND.

